The present invention relates to monitoring operation of a locomotive, and more particularly to monitoring the starting, stopping and/or idling of a locomotive with a view towards conserving fuel.
In recent years, locomotives have been equipped with systems for automatically starting and stopping their engines when predefined conditions exist. The primary purpose of such systems is to conserve fuel, thereby lowering fuel costs while also preserving precious energy resources. For instance, a locomotive may be configured to automatically shutdown after operating a certain amount of time in parked idle so as to prevent the locomotive from needlessly wasting fuel. The locomotive may then automatically restart when, for example, an operator signals an intention to motor the locomotive, such as by moving a direction controller (known as a reverser) from a center position (that is, from a xe2x80x9cneutralxe2x80x9d position). A locomotive may also be configured to automatically restart a certain amount of time following an automatic shutdown, such as two or four hours, or when other conditions exist.
The automatic engine start and stop (AESS) system described above has been implemented not only in locomotives which operate independently, but also in multiple locomotives that operate together (i.e., in consist) for providing cumulative (or reserve) towing capacity. The front locomotive in the consist is usually designated the lead unit while the other locomotives are designated trail units. Each trail unit typically receives a trainline signal representing the position of the lead unit""s reverser, and treats that signal as representing the position of its own reverser (which is typically placed in the center position when configuring the locomotive for trail unit operation). In the case where a locomotive""s reverser must be in the center position to activate the AESS system, placing the lead unit""s reverser in the center position will activate the AESS system in each locomotive in the consist. Similarly, in the case where moving an automatically shutdown locomotive""s reverser from the center position induces an automatic engine restart, moving the reverser in an automatically shutdown lead unit from the center position induces an automatic restart for each automatically shutdown locomotive in the consist.
Although deployed AESS systems have proven reliable, the inventors hereof have discovered human factors that result in unrealized fuel savings. For example, they discovered that operators frequently take steps to prevent automatic engine shutdowns. This is apparently done so that lead units (including single units operating independently and not in a consist) remain available upon demand (i.e., for operator peace of mind), and to provide climate control (e.g., heating and air conditioning) to the operator cabin. Common approaches to preventing automatic engine shutdowns include maintaining a lead unit""s reverser out of the center position, and manually moving an automatic start/stop disable switch (ASDS), typically located in a CA1 locker, to an xe2x80x9coffxe2x80x9d position. Service personnel may also forget to move the ASDS to its xe2x80x9conxe2x80x9d position after switching it xe2x80x9coffxe2x80x9d for safety during maintenance procedures. Regardless of how or why it occurs, preventing an AESS system in a single locomotive from performing its intended function obviously results in lost fuel savings. Moreover, preventing an auto shutdown in the lead unit of a consist may prevent an auto shutdown for each trail unit in the consist. Thus, although an operator may, for example, maintain the lead unit""s reverser out of the center position for the sole purpose of keeping the lead unit running, the net result may be that two, three, or even more trail units remain running and consuming fuel, in addition to the lead unit.
A related problem discovered by the inventors is unnecessary operator induced restarts, which occur, for example, when an operator moves the reverser of an automatically shutdown locomotive away from the center position. The apparent reasons for such restarts are essentially the same as those for preventing automatic engine shutdowns, namely, to resume on-demand availability of lead units and to provide climate control to the operator cabin. Again, while an operator""s intention may be to simply restart a lead unit, the effect may be to restart every locomotive in a consist.
There are also conditions generally unrelated to locomotive operators which may prevent a locomotive equipped with an AESS system from initiating an automatic shutdown. For example, many railroad companies require their locomotives to operate in parked idle for some minimum amount of time, such as ten or thirty minutes, prior to an automatic shutdown. Similarly, locomotives may be required to run or idle for some minimum amount of time following an automatic restart, such as for two hours, before the locomotive is permitted to again shutdown automatically. Additionally, many AESS systems will not initiate an automatic shutdown if, for example, ambient and engine oil temperatures are not within predefined ranges, or if a locomotive fault is detected, or if the locomotive""s distributed power unit is on, etc. Thus, any one of a number of conditions may prevent an automatic engine shutdown, some of which are operator dependent and some of which are not.
Currently deployed AESS systems monitor a limited number of parameters related to automatic engine shutdowns and restarts. For example, they typically monitor how long a locomotive is automatically shutdown, how long a locomotive""s AESS system is disabled (due to the ASDS position), as well as the amount of time that certain other parameters (e.g., engine oil temperature, ambient temperature, battery charging current, etc.) are out-of-range. As recognized by the inventors hereof, however, operators may prevent automatic shutdowns without disabling their AESS systems. Thus, how long an AESS system is disabled does not necessarily equate to how long an automatic shutdown is prevented by an operator. The inventors have also recognized that several monitored parameters may be out-of-range at the same time. Thus, how long each monitored parameter is out-of-range does not necessarily reveal how long such parameters as a group prevent an automatic shutdown.
For these and other reasons, the inventors have recognized a need to monitor locomotive operating conditions and events in closer detail so that, among other things, various causes of lost fuel savings may be more specifically identified and addressed.
In order to solve these and other needs in the art, the inventors hereof have designed a locomotive monitoring system that preferably defines several mutually exclusive operating states. At any given time, the locomotive is deemed to be operating in one and only one of these operating states. The total amount of time that the locomotive operates in each state is preferably determined and recorded. This recorded information can then be evaluated with a view towards improving locomotive operations. For example, a plurality of mutually exclusive idle states can be defined and monitored to determine how long a locomotive idles under certain conditions instead of automatically shutting down for the purpose of conserving fuel. In this manner, the sources of lost fuel savings can be readily identified, quantified and addressed. An event log is also provided for chronicling certain operating events of interest over time, such as those relating to the starting, stopping and/or idling of the locomotive""s engine.
According to one aspect of the present invention, a locomotive monitoring system includes a memory device for storing computer instructions and a computer processor for executing the computer instructions stored in the memory device. The computer instructions define a plurality of mutually exclusive idle states. The locomotive operates in one of the mutually exclusive idle states when idling. The computer instructions configure the computer processor to determine how long the locomotive operates in each of a plurality of the mutually exclusive idle states, and to record data indicative thereof in the memory device.
According to another aspect of the present invention, a method of monitoring operation of a locomotive having an automatic engine start/stop (AESS) system includes: defining a plurality of mutually exclusive idle states, the locomotive operating in one of the mutually exclusive idle states when the locomotive""s engine is idling; monitoring how long the locomotive operates in each of a plurality of the mutually exclusive idle states; and recording results of the monitoring.
According to yet another aspect of the invention, a method of monitoring operation of a locomotive having an automatic engine start/stop (AESS) system includes: defining a plurality of events related to automatic starting or stopping of the locomotive""s engine; monitoring operation of the locomotive; and recording event data when one or more of the defined events occur.
According to a further aspect of the invention, a method of monitoring a locomotive configured to automatically shutdown its engine when predefined shutdown parameters are satisfied includes: defining a parameter set to include at least two of the predefined shutdown parameters; measuring a duration of time commencing when any one or more parameters of the defined parameter set are not satisfied and ending when each parameter of the defined parameter set is satisfied; and recording the measured duration of time.
According to still another aspect of the invention, a computer-readable medium has computer-executable instructions recorded thereon for implementing any one or more of the systems and methods described herein.
Other aspects and features of the present invention will be in part apparent and in part pointed out hereinafter.